1. Field of the Invention
The present invention relates to a piercing terminal which penetrates into a flat circuit body such as FPC (Flexible Print Circuit) or FFC (Flexible Flat Cable) for electrically connecting with a conductor thereof, and relates to a connector having the piercing terminal.
2. Description of the Related Art
A vehicle has a variety of electronic devices. Electric power from a battery and signals from control devices are transmitted to the electronic devices through a wiring harness. The wiring harness has a FFC 50 and a connector 51 connected with the FFC 50 as shown in FIGS. 20A and 20B. For example, refer to JP,2002-334617,A or JP,2549583,Y.
The FFC 50 includes a plurality of conductors 52 juxtaposed to each other and an insulating sheath 53 for insulating the conductors 52 each other. The conductors 52 are made of a copper alloy such as brass and are conductive. The insulating sheath 53 is formed with PET(Polyethyleneterephthalate).
An end portion of the FFC 50, which is received in a connector housing 56 of the connector 51 as described later, has a cutout portion 54 which is positioned between the conductors 52. As shown in FIG. 21A, the cutout portion 54 is shaped to be fitted with a shape of the connector housing 56. The cutout portion 54 is disposed between the conductors 52.
The connector 51 has a female terminal (hereafter called terminal) 55 and the connector housing 56. As shown in FIGS. 20B and 21A, the terminal 55 has the conductors 52 of the FFC 50, a wire connecting portion 58, and an electric contact portion 59 connected with the wire connecting portion 58. The wire connecting portion 58 has a bottom wall 60a and crimp edges 61 upstanding from the bottom wall 60a. 
As shown in FIG. 21B, the crimp edges 61 penetrate through the conductors 52 and the insulating sheath 53, and crimp the FFC 50. Accordingly, the crimp edges 61 are electrically connected with the conductors 52 of the FFC 50.
Each electric contact portion 59 has a bottom wall 60b connected with the bottom wall 60a of the wire connecting portion 58. The electric contact portion 59 accepts a strip-shaped male tab (not shown) and is electrically connected with the male tab. The terminals 55 are received in the connector housing 56 and are fitted with the male terminals so that the conductors 52 of the FFC 50 and the male terminals are electrically connected.
The connector housing 56 has a tube-shaped main body 63 and a retainer 64 to be attached to the main body 63. The main body 63 has a partition 65 which separates the main body 63 into a plurality of terminal receiving rooms 66. The cutout portion 54 is positioned to the partition 65 and the terminal receiving rooms receive the terminals 55.
An end portion of the retainer 64 is received in the main body 63 so as to press the FFC 50 connected to the terminals 55. Accordingly, the connector housing 56 positions the cutout portion 54 to the partition 65 and receives the end of the FFC 50 crimped to the terminals 55 with the crimp edges 61 in the terminal receiving room 66.
The connector housing 57 of FIG. 22 has the tube-shaped main body 63 and slits 67 disposed in the main body 63. The slits 67 are formed in the main body 63 to correspond to a shape of the FFC 50 and extend into a longitudinal direction of the main body 63 and receive the end portion of the FFC 50 crimped to the terminals 55. The connector housing 56 having the terminals 55 is fitted into a mating connector housing (not shown) receiving male terminals.
In the conventional terminals 55, in order to crimp the FFC 50 to the terminals 55 with the crimp edges 61, each terminal 55 is placed between metal frames 68 and approached to the FFC 50 as shown in FIG. 23A.
The conventional terminal 55 has the upstanding crimp edges 61 at the bottom wall 60a so that the terminal 55 becomes longer. In the conventional terminal 55, the electric contact portion 59 extends forwardly from the end portion of the FFC 50 so that the terminal 55 can not be easily handled. In the conventional FFC 50, the cutout portion 54 thereof reduces the strength of the FFC 50.
When the terminal 55 is positioned between the metal frames 68, there often occurs gaps A between inner walls 69 of the metal frames 68 and outer walls 70 of the terminal 55, as shown in FIG. 23A. Accordingly, when the terminal 55 is approached to the FFC 50, the crimp edges 61 incline at an angle of θ corresponding to the gaps A. Namely, the terminal rolls. When the terminal 55 rolls, the crimp edges 61 do not penetrate perpendicularly to the FFC 50.
This causes a clearance between the crimp edges 61 and the FFC 50 when the crimp edges 61 penetrate the FFC 50 and are bent. As a result of that, the electrical connection between the terminal 55 and the conductor 52 of the FFC 50 becomes unstable. In order to avoid the rolling of the crimp edges 61, the length thereof can be made longer. However, the long crimp edges 61 reduces the rigidity and are easily bent when the crimp edges 61 penetrate into the FFC 50.